This invention relates generally to electric cigar lighter devices, and more particularly to electrical connector receptacles for such devices, by which the energizing current is brought to the cigar lighter socket.
In the past a number of different arrangements have been proposed and produced for effecting the electrical connection to the sockets of cigar lighters. As a rule such devices employ a centrally disposed stud at the rear of the socket, this terminal constituting the "hot" side of the lighter circuit. Connection to the other or ground side was made in a variety of ways. In early model vehicles where such lighters were mounted on metal dashboards, the bezel of the socket was in electrical contact with the walls of the mounting hole, with the dashboard being at electric ground potential. Generally such sockets carried tubular clamping shells which engaged the rear surface of the dash, thus providing both a mechanical mounting for the socket as well as an additional electrical path for the current being drawn.
With the advent of newer model vehicles, widespread use of plastic panels has evolved. Under circumstances where the mounting panel for the lighter is not metal, it is necessary to run a separate lead to the ground side of the lighter socket. This has been accomplished in many cases by means of a spade lug welded to the clamping shell of the socket, and a cooperable, separable push-on type space terminal connected to the vehicle ground. Such an arrangement has performed well over the past 10 years or so, and has won relatively wide acceptance in the industry. Generally the length of the lead extending from the push-on terminal to the vehicle ground or chassis was relatively short, frequently being on the order of a foot or less. The only requirement was that the other end of the lead be fastened to a sheet metal part of the vehicle by a suitable fastener such as a self tapping screw, etc.
There are, however, several disadvantages with the arrangement described above. The area around the lighter was sometimes not readily accessible, and installation or replacement of the push-on spade terminal was difficult or awkward. In addition, there existed a possibility of such push-on terminals loosening somewhat after repeated installations, or being subject to damage, if forced. Also, these terminals were susceptible of being inadvertently "sprung", resulting in poor mechanical and electrical contact. Problems also occurred involving corrosion of the spade lug, especially after an extended period of time, thus jeopardizing the integrity of the connnection.
Added to the above disadvantages was the extra cost of welding a spade lug onto the clamping shell for the socket. This necessitated replating of the area surrounding the weld, in order to avoid undesirable corrosion and also to maintain a clean, finished appearance.
Finally, there existed the possibility of the lead carrying the push-on spade terminal inadvertently loosening, or being left off entirely, thus leaving the ground side of the circuit floating and rendering the lighter inoperative.